Within the field of tool holders used in grooving and parting operations, there are many examples of cutting inserts being clamped in an insert receiving pocket of a narrow blade-shaped holding portion between a rigid base jaw and a flexible clamping jaw. Some of these tool holders are configured such that the cutting insert is actively clamped between the clamping jaw and the base jaw by means of a clamping member.
U.S. Pat. No. 3,894,322 discloses such a tool holder having a rectangular shank and a head at the forward end thereof. The front side of the head is in the form of a narrow vertical wall with a forwardly opening recess for receiving a cutting insert. The recess includes parallel upper and lower edges and an interconnecting semi-circular back edge. A horizontal slot extends rearwardly from the back edge to a circular slot end in the shank, thus dividing the head into upper and lower jaws. Rearward of the narrow vertical wall, a bolt passes through a clearance hole in the upper jaw and engages a tapped hole in the lower jaw. When tightened, the bolt draws the upper and lower jaws together and clamps the cutting insert within the recess. The depth of insertion of the tool holder is limited by the amount of force that can be efficiently transmitted from the tightening of the bolt to the clamping of the cutting insert.
U.S. Pat. No. 5,360,298 discloses a tool holder in the form of a thin plate or plate-like part, having a recess for receiving a cutting insert, the recess being defined by a bottom wall, a rear wall, and an upper wall which is part of an elastically movable clamping arm. From the rear wall extends a comparatively narrow slot, and a clamping screw passes through a substantially vertical hole in the clamping arm and engages a threaded hole in the plate under the slot. The clamping arm serves to clamp the cutting insert against the bottom wall by tightening the clamping screw. The threaded hole in the plate under the slot may inherently weaken the structure of tool holder and limit its operational range. Also, inclusion of a coolant duct extending along the length of the clamping arm may be restricted by the vertical hole.
It is an object of the present invention to provide an improved and more robust tool holder.
It is also an object of the present invention to provide a tool holder configured to provide efficient active clamping of a cutting insert in an insert receiving pocket. It is a further object of the present invention to provide a cutting tool configured to perform grooving and parting operations at a large depth of insertion relative to the holder width.
It is still a further object of the present invention to provide a cutting tool which can be configured to direct coolant from a coolant duct in close proximity to the operative cutting edge of a cutting insert assembled therein.